Flexible key



March 31, 1936. H. DENULL 2,035,798

FLEXIBLE KEY Filed June 1, 1934 J12 U672 for:

A M fiww 4 4 A Ov -'7 Patented Mar. 31, 1936 PATENT OFFICE FLEXIBLE KEY Hans Denull, Berlin-Charlottenburg, Germany,

assignor to Heinrich Goldbeck, Berlin, Germany Application June 1, 1934, Serial No. 728,534 In Germany February 6, 1932 1 Claim. (01. 70-9) This invention relates to a key for certain locks, especially for locks such as described in application Serial Number 655,099.

The key according to the invention must withstand the same stressing in both directions of rotation. For this purpose the key shank is composed of separate hingedly connected elements. These separate elements are stifl'ened mutually and with the key handle by resilient means, such as wires extending through inner bores in the elements and each individual element has at one end a divided cylindrical projection'which engages in a corresponding recess in the neighbouring element. It is evident that instead of employing individual elements of the shape described other shaped separate elements connected by universal joints may be employed.

Further features of the invention are hereinafter set forth.

An embodiment of the invention is illustrated by way of example in the accompanying drawing in which:-

Fig. 1 is an elevation showing the key with its shank in straight position and covered by a shank protecting sleeve shown in section.

Fig. 2 shows the key in bent position.

Fig. 3 is an elevation showing the key turned through 90 as compared with Fig. 2.

Fig. 4 shows detailed views of two shank elements with central bore.

Fig. 4a shows in elevation the key in straight position turned through 90 as compared with Fig. 1.

Fig. 5 is a longitudinal section through a further form of construction which ensures the proper insertion of the key without feeler knob.

Fig. 5a. shows in elevation a portion of the key guide channel.

Fig. 6 is a similar view to Fig. 5 showing the,

key turned through 90.

Fig. 7 shows the cover plate employed with this lock.

A key the shank of which is composed of twisted wire, rope laid wire, or the like, often sticks in the guide so that the handle cannot be turned when the barb is held.

The key according to the invention consists of a shank portion composed of individual hingedly connected elements, which elements are reinforced to form a complete unit by pliable means, such as wires 2| extending through central bores H3 in the individual elements and connecting the key bit, which is preferably of cross-shaped cross section, with the key handle.

The interengagement of the individual elements 20 is clearly shown on the drawing and Figs. 1 to 4 show that it is possible to turn the key shank 8 in all directions. Such a key can withstand strong bending and torsional stresses without any danger of breaking. 5

As can be seen from this Fig. 4a, the handle 9 and the bit II have central bores 90 and Ila respectively, the bore Ha terminates in the middle of the bit length and the bore 9a in the middle of the handle, that is according to Fig. 6 ex- 0 tends up to the riveted end of the handle 9. The wire 2| extending through all the central bores H! of all the individual elements 20 into the bore I la of the bit II. It also projects from the element 20 nearest the handle 9. This pro- 15 jecting wire end is of such length that, when the handle 9 is fitted in position, it is in the central bore 9a thereon. The plate of the handle 9 carrying the feeler projections I0 is then inserted in the slot 9b and riveted in position so 20 that the wire extends through all the individual elements and one of its ends fits loosely in the bore H a in the bit ll, whereas its other end fits loosely in the bore 9a of the handle 9. As the individual elements 20 owing to their shape 25 shown in Fig. 4, that is by the provision of cylindrical hinge connections, cannot become detached in the longitudinal direction of the shank, it is not necessary for the ends of the wire to be fixed in any way because the wire does not 30 have to hold the elements together. It is not possible to disengage the individual elements 20 lateraly because the wire prevents this movement by immediately coming into contact with the wall of the bore l9. The wire also serves 35 for maintaining the elements 20 in rigid position, that is keeps the shank in almost a straight line as shown in Fig. 1 to facilitate the insertion of the bit in the keyhole.

The key handle is preferably provided with 40 feeler knobs, two feeler knobs I0 according to Fig. 1 must be directed towards the jamb edge of the door to ensure the proper positioning of the bit relative to the lock.

The key channel preferably extends upwards 45 so that a blocking of the guide channel by the insertion of pieces of metal or other articles and also the penetration of dust and dirt is prevented.

In order to ensure the proper insertion of the 50 flexible key feeler knobs may be provided on the key handle according to the constructions shown in Figs. 1 to 4 or on the key element connected to the key handle a projection 40 is provided which is so situatedthat premature and incorrect penetration of the bit into the lock is prevented.

The key can therefore only be inserted in the proper position in which the key bit is situated in a position ready for inserting into the locking mechanism. The key, after its projection has been once inserted, can be turned without diniculty when the key bit has completely entered the lock and the key can only be removed after the locking or unlocking movement has been completed.

Finally, the locking mechanism cannot be tampered with so that premature wear, especially of the brass parts of a lock cylinder, is prevented and it is no longer necessary to make the inserting slots of different width 'or length, but they can be made uniformly so that the cost of production of the lock and of the key bit, the arms of which may be of uniform thickness, is reduced.

In the form of construction illustrated in Figs. 5 to '7 8 designates the usual flexible key 9 is the key handle, the feeler knobs mentioned in the previous constructions being replaced by a projection 40 and guide groove 4!. The length of the guide groove 4| plus the length of the projection 40 corresponds approximately to the length inder lock 43.

the projection 40, which bears against the edges.

44 of the annular groove 62, prevents this.

Fig. 6 illustrates the key turned through The key 9 can therefore not be pulled out in this position. v

The mouth of the insertion groove 4| together with the key channel is preferably closed by a cover 45, which is rotatably mounted on a bolt 46. The end of the spring loaded bolt 46 projects into the interior of the lock case 2. The cover has an aperture 41 so that in the position indicated in dotted lines in Fig. 6 it snaps on to the projection 48. Such a cover can only be opened by initiated persons. The cover is slightly lifted by inserting the finger nail or some other article under the bevelled edge 49, thereby compressing the spring 50, whereupon the cover is turned into its open position, where it is again locked by the spring 50 which is so strong that it holds the cover in position. The closing of the cover is efiected practically automatically by the presence of suitable conical, substantially semi-circular recesses ii in the inner side of the cover edge, without it being necessary to-lift the cover over the snap knob 48. The cover cannot be moved backwards and forwards when in closed position, but it is necessary to lift it away from the knob 48 by means of its bevelled edge 49.

Should it happen that in spite of this closing cover 45 the lock channel is blocked with paper or other articles, these can be removed by the fact that the channel walls 52 are provided with apertures 52a through which small paper balls or the like drop.

The first link of the flexible key shank (Fig. 6)

can for example be employed as projection 40 in that it is extended beyond its normal width towards one side. i

According to the invention the internal arrangement of the lock is also simplified in that special tumbler pins of a diiferent thickness to the tumbler pins which were hitherto intended to prevent the removal of the key when the lock is not completely unlocked or locked, are unnecessary as merely the projection 40 which serves in this instance as abutment against the inner casing edge 44 effects this work.

The point I l of the key cannot be moved backwards and forwards, that is pushed in and out in the lock 43 as the backward movement is prevented by the abutment 40 and the forward movement by the closing disc 85.

Owing to the outward pressing of the pin 66 by means of the inclined notches 61 in the key bit II the bore edges 88 would be'prematurely damaged and thus the perfect and accurate working of the lock detrimentally aflected. This objection is, as already mentioned, also overcome by the invention.

I claim:

A flexible key, comprising in combination a shank composed of a plurality of individual hingedly connected elements interconnected and each having a central bore, a bit hingedly mounted on one end of said shank, and a handle hingedly mounted on the other end of said shank, and a pliable member connecting said bit to said handle and extending through the central bores in said elements, said pliable member adapted to securely hold said elements in engagement to enable said shank to withstand the same pressure in both directions of rotation.

HANS DENULL. 

